import Vue from 'vue'
import VueRouter from 'vue-router'
const Login = () => import('../components/login.vue')
const Home = () => import('../components/home.vue')

Vue.use(VueRouter)

const routes = [
  {
    path:'/',
    redirect:'/login',
  },
  {
    path: '/login',
    component: Login
  },
  {
    path: '/home',
    component: Home
  }
]

const router = new VueRouter({
  routes,
  module:'history'
})

router.beforeEach((to,from,next)=>{
  // to 将要访问的路径
  // from 代码从哪个路径跳转而来
  // next 是一个函数 表示放行
  // next 放行 next('/login) 强制转换
  
  //如果用户访问登陆页面 直接放行 
  if(to.path === '/login') return next();

  const tokenStr = window.sessionStorage.getItem('token')
  // 没有token强制跳转到登录页
  if(!tokenStr) return next('/login');
  next();
})

export default router
